Department of Pathology, Southeast University, Zhongda Hospital, Nanjing 210009, P R China.
BMC Cancer. 2013 Jun 14;13:290. doi: 10.1186/1471-2407-13-290.
Our previous studies showed that SIRT1 was over-expressed in gastric cancer specimens and related with lymph node metastasis. However, the mechanism of SIRT1 up-regulation and its association with metastasis in gastric cancer remain unclear. The present study was undertaken to understand the role of microRNA in regulation of SIRT1 in the progression of gastric cancer.
Expression of miR-204 and SIRT1 was assessed in two gastric cancer cell lines and 24 matched cancer specimens. Luciferase reporter assay was carried to verify that miR-204 targeting SIRT1. Cell invasion ability of AGS and BGC was detected by transwell invasion assay. Annexin V/PI assay was used to investigate the cell sensitivity of anoikis. Western blot analysis to assess SIRT1, Vimentin, E-Cadherin, LKB1, and β-actin expression was performed in gastic cancer cell lines.
SIRT1 was defined as the target gene and elucidated the biological functions of miR-204 with a luciferase reporter assay and Western blot analysis. We verified that miR-204 levels were down-regulated and significantly associated with the up-regulation of SIRT1 mRNA levels in gastric cancer specimens. Over-expression of miR-204 reduced cell invasion and anoikis resistance in gastric cancer cells. Up-regulation of miR-204 influenced the levels of the epithelial mesenchymal transition (EMT)-associated genes, increasing E-cadherin levels and decreasing Vimentin levels. We demonstrated that the regulation of EMT by miR-204 involves cooperation with LKB1. Furthermore, silencing of SIRT1 phenocopied the effects of miR-204 in gastric cancer cells. These data demonstrate that miR-204 plays an important role in regulating metastasis of gastric cancer, which is involved in post-transcriptional repression of SIRT1.
Our results suggest that down-regulation of miR-204 promotes gastric cancer cell invasion by activating the SIRT1-LKB1 pathway. These data demonstrate that miR-204 plays an important role in regulating metastasis of gastric cancer, which is involved in post-transcriptional repression of SIRT1.
我们之前的研究表明，SIRT1 在胃癌标本中过度表达，与淋巴结转移有关。然而，SIRT1 上调的机制及其与胃癌转移的关系尚不清楚。本研究旨在了解 microRNA 在调节胃癌中 SIRT1 表达中的作用。
在两种胃癌细胞系和 24 对匹配的癌标本中评估 miR-204 和 SIRT1 的表达。通过荧光素酶报告实验验证 miR-204 靶向 SIRT1。通过 Transwell 侵袭实验检测 AGS 和 BGC 的细胞侵袭能力。用 Annexin V/PI 检测细胞失巢凋亡敏感性。用 Western blot 分析检测胃癌细胞系中 SIRT1、波形蛋白、E-钙黏蛋白、LKB1 和 β-肌动蛋白的表达。
SIRT1 被定义为靶基因，并通过荧光素酶报告实验和 Western blot 分析阐明了 miR-204 的生物学功能。我们验证了 miR-204 水平下调与胃癌标本中 SIRT1 mRNA 水平上调显著相关。miR-204 的过表达降低了胃癌细胞的侵袭和抗失巢凋亡能力。miR-204 的上调影响上皮间质转化（EMT）相关基因的水平，增加 E-钙黏蛋白水平，降低波形蛋白水平。我们证明了 miR-204 通过与 LKB1 合作调节 EMT。此外，沉默 SIRT1 可模拟 miR-204 在胃癌细胞中的作用。这些数据表明，miR-204 在调节胃癌转移中起重要作用，这涉及 SIRT1 的转录后抑制。
我们的结果表明，miR-204 的下调通过激活 SIRT1-LKB1 通路促进胃癌细胞侵袭。这些数据表明，miR-204 在调节胃癌转移中起重要作用，这涉及 SIRT1 的转录后抑制。
